1. Field of the Invention
This invention relates to an air conditioning device for cooling and heating the air in a cabin of an earth-moving vehicle such as bulldozer, shovel loader, or the like.
2. Description of the Prior Art
A known device consists, as shown in FIG. 1, of installing an air conditioning device C on the ceiling of a cabin B of an earth-moving vehicle A, connecting the air conditioning device C to the engine via conduits D, and blowing hot air or cold air into the cabin to cool or heat the air in the cabin B.
With the device being constructed as described above, however, the conduits D must be removed when the cabin B is to be removed from the car body. Namely, to remove the cabin involves cumbersome operation. Further, when a filter for introducing the external air is to be cleaned, the operator must detach or attach the filter by climbing the ceiling of the cabin; i.e., cumbersome operation is required for detaching and attaching the filter when it is intended to clean the filter. Cumbersome operation is further required for the servicing and maintenance of the air conditioning device. Moreover, strong vibration is produced via the cabin B. Furthermore, the air conditioning device must be strongly constructed so as not to be damaged even in case rocks or the like fall thereon. Because of these reasons, the air conditioning device becomes costly.
Further, since the air conditioning device is installed on the ceiling of the cabin, the cold air or the hot air at the time of cooling or heating is blown downwards from the side above the head of the operator. Therefore, the floor side is not efficiently cooled or heated, and the feet of the operator are not effectively cooled or heated. This difficulty appears conspicuously when the feet are to be heated.
It can therefore be contrived to install the air conditioning device C at the back of the operator's seat in the cabin B, or by the side of the operator's seat, or in front of the operator's seat. If installed at the back of the operator's seat, however, the air conditioning device (particularly conduits) must be removed when units (such as transmission and the like) located under the driver's seat are to be removed or adjusted, making the operation cumbersome. If installed by the side of the operator's seat, the air conditioning device hinders the operator from getting in or out of the cabin. If the air conditioning device is installed in front of the operator's seat, space is reduced in front of the operator's seat. Therefore, the operator finds it uneasy to be in the cabin and, further, loses sight in the forward direction.
Further, no matter where the air conditioning device is installed among the above-mentioned places, the air blow port and the internal air intake port are located close to each other, creating the flow of the air only in a local portion in the cabin. Therefore, the cold air or the hot air is readily intaken, making it difficult to efficiently cool or heat the air in the cabin.